Heat-transfer device and method to produce such a device

Abstract

A heat-transfer device includes a bi-porous wick having at least one layer including a micro-porous body and tubular macro-pores, and a dense casing enclosing the wick, wherein the body and the macro-pores are fluidically interconnected and are at least partially overlapping inside the layer.

1 . A heat-transfer device comprising:
 a bi-porous wick having at least one layer comprising a micro-porous body and tubular macro-pores, wherein the tubular macro-pores are arranged in the micro-porous body and are differently oriented, and   a dense casing enclosing the wick,   wherein the body and the tubular macro-pores are fluidically interconnected and are at least partially overlapping inside the layer, and   wherein surfaces of the tubular macro-pores are made out of a micro-porous material of the micro-porous body.   
     
     
         2 . (canceled) 
     
     
         3 . The heat-transfer device according to  claim 1 , comprising at least one evaporator area inside the casing and at least one condenser area inside the casing, wherein the bi-porous wick fluidically interconnects the condenser area with the evaporator area. 
     
     
         4 . The heat-transfer device according to  claim 1 , wherein the body has a pore size between 80 μm and 5 μm. 
     
     
         5 . The heat-transfer device according to  claim 1 , wherein the macro-pores have a diameter between 0.3 mm and 0.1 mm. 
     
     
         6 . The heat-transfer device according to  claim 1 , wherein the wick comprises differently sized macro-pores arranged in different layers of the wick. 
     
     
         7 . (canceled) 
     
     
         8 . The heat-transfer device according to  claim 1 , wherein the differently oriented macro-pores are fluidically interconnected. 
     
     
         9 . The heat-transfer device according to  claim 1 , wherein the wick is selectively sintered from loose metal powder grains by additive manufacturing. 
     
     
         10 . The heat-transfer device according to  claim 1 , wherein the wick is connected to the casing and the casing is sintered integrally with the wick. 
     
     
         11 . A method to produce a heat-transfer device, the method comprising:
 steering an energy beam targeted at a surface of a feedstock of loose metal powder grains over an expanse of a wick of the heat-transfer device to heat near-surface grains forming the wick to a sintering temperature of metal of the loose metal grains and fuse the heated grains to a micro-porous body of the wick wherein an energy exposure of the grains forming the body is limited to a sintering energy density and the grains in macro-pores of the wick are circumnavigated by the energy beam, and steering the energy beam over an expanse of a casing of the heat-transfer device to heat the near-surface grains forming the casing to a melting temperature of the metal and melt the grains to the casing, wherein the energy exposure of the grains forming the casing equates at least a melting energy density.   
     
     
         12 . The method according to  claim 11 , wherein the grains in the macro-pores are removed after the grains forming the body have fused. 
     
     
         13 . The method according to  claim 11 , wherein the wick is moisturized with a fluid, and wherein an atmosphere inside the casing is adjusted to set a phase-change temperature of the fluid.